Polymerization of α-olefins

ABSTRACT

A catalyst for the solution polymerization of α-olefins is prepared by admixing component (A) with an organometal component (B), component (A) being prepared by reacting a specific hydrocarbon-soluble organomagnesium compound with an aluminum compound and contacting the obtained product with a titanium and/or vanadium compound.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a process for polymerizing an α-olefin in liquid phase using a novel catalyst.

2. Description of the Prior Art

It is known that solution polymerization is suitable for the production of polyethylene and its advantages are as follows:

(1) The polymerization of ethylene is an exothermic reaction and removal of heat is a big problem from the viewpoint of a process. Since the efficiency of removing heat increases with greater differences between the inner temperature of a reactor and that of a cooling jacket, solution polymerization in which a high polymerization temperature is employed is advantageous from this point.

(2) The degree of polymerization of ethylene, i.e. the molecular weight of polyethylene can be controlled comparatively accurately by varying the polymerization temperature and furthermore, the control of the molecular weight of polyethylene can be done by using a small amount of hydrogen.

(3) Since the molecular weight of polyethylene is correlated with the viscosity of the reaction solution, it can be estimated by measurement of the viscosity of the reaction solution in the reactor and the control of the molecular weight of polyethylene can be quickly done accordingly.

(4) Polyethylene is used or sold usually in the form of pellets. The polyethylene obtained by suspension polymerization and gas phase polymerization is powdery and it is necessary to melt-mold the powdery polyethylene into pellets by an extruder. On the other hand, according to solution polymerization it is possible to remove the polymerization solvent by evaporation with the use of the heat of polymerization and to introduce the polyethylene in its melt form into an extruder. As a result, excess step and heat for melting the polyethylene can be omitted. In order to make the most of this advantage, it is preferred that the polymerization temperature is high.

The disadvantage of solution polymerization is an increase in the solution viscosity due to the increase in the solution concentration or the molecular weight of polyethylene, which renders commercial scale production of polyethylene difficult. In order to avoid this disadvantage, it is necessary that the polymerization temperature is raised and simultaneously the solution viscosity is reduced. However, with increased polymerization temperatures the catalyst efficiency is decreased and a large amount of catalyst residue remains in the formed polyethylene and causes discoloration of the polyethylene and deterioration of molded articles obtained therefrom. Further, removal of the catalyst residue is difficult. Thus, there are required catalysts having a high catalyst efficiency at high temperatures which enable complete omission of the catalyst removal step due to the small amount of the catalyst residue present in the formed polyethylene.

There are known many Ziegler type catalysts having a high catalyst efficiency for suspension polymerization (see, e.g. U.S. Pat. Nos. 4,115,319, 4,159,965 and 4,163,831). However, the catalyst efficiency of these catalysts is, in general, decreased with increased polymerization temperatures, and especially at temperatures higher than about 150° C., the decrease in the catalyst efficiency is remarkable. Thus the performances of such catalysts are not enough to omit the removal step of catalyst residue when employed in solution polymerization.

There are also known catalysts for solution polymerization of an olefin which comprise an organomagnesium complex, an aluminum halide, hydrogen chloride, a halogenated secondary or tertiary alkyl or halogenated silicon compound and a titanium compound (see, e.g., U.S. Pat. Nos. 4,159,965 and 4,172,050 and U.K. Pat. Nos. 1,251,177 and 1,235,062). These catalysts have a higher catalyst efficiency than the conventional catalysts but their catalyst efficiency at high temperatures is still insufficient.

As a result of the study on the catalyst system for solution polymerization it has been discovered that by using, as a catalyst, a component having been obtained by reacting a specific organomagnesium compound with an aluminum compound and contacting the obtained product with a titanium compound and/or a vanadium compound, in combination with an organometal component, there can be obtained catalysts having a very high catalyst efficiency without any decrease at least at 120° C., especially at least at 150° C., and an excellent storage stability suitable for the polymerization of an olefin.

SUMMARY OF THE INVENTION

Accorcing to this invention there is provided a process for polymerizing an α-olefin comprising contacting the olefin in liquid phase at a temperature of about 120° to about 320° C. with a catalyst comprising a component (A) and an organometal component (B), the component (A) being produced by reacting a hydrocarbon-soluble organomagnesium component (i) of the formula,

    M.sub.α MgR.sub.p.sup.1 R.sub.q.sup.2 X.sub.r.sup.1 X.sub.s.sup.2 D.sub.t

wherein

α, p, q, r, s and t each independently is 0 or a number greater than 0,

p+q+r+s=mα+2

0≦(r+s)/(α+1)<2,

m is the valence of M,

M is a metal of the 1st to 3rd groups of the Periodic Table,

R¹ and R² each independently is a hydrocarbon group having

1 to 20 carbon atoms,

X¹ and X² each independently is a hydrogen atom or an organic electronegative group containing O, N or S,

D is an electron donor, with an aluminum compound (ii) of the formula,

    AlX.sub.x.sup.3 Y.sub.y

wherein

X³ is OR³, OSiR⁴ R⁵ R⁶, NR⁷ R⁸ or SR⁹ wherein R³ and R⁹ each independently is a hydrocarbon group having 1 to 20 carbon atoms and R⁴, R⁵, R⁶, R⁷ and R⁸ each independently is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms,

Y is a halogen atom,

x and y each independently is a number greater than 0 and less than 3,

x+y=3,

and contacting the product of (i)+(ii) with (iii) a compound of titanium and/or a compound of vanadium at a concentration of titanium plus vanadium of at most about 2 mols per liter of the inert reaction solvent, the atomic ratio of Mg/(Ti+V) in (A) being about 3 to about 500.

One of the characteristic features of this invention is a high catalyst efficiency which reaches at least 200 Kg/g(Ti+V).Hr as will be illustrated by the Examples. Accordingly, the step of removing catalyst residue can be omitted.

Another characteristic feature of this invention is that the catalyst of this invention is stable at high temperatures and the catalyst efficiency reaches 200 Kg/g(Ti+V).Hr at a temperature of 150° C. or higher than 150° C.

Still another characteristic feature of this invention is that there can be obtained polymers having a narrow molecular weight distribution, a high molecular weight and a high rigidity suitable for injection molding due to the use of the above described aluminum compound (ii). It is possible to produce polyethylene having a flow ratio of less than about 20 which means a very narrow molecular weight distribution as will be illustrated by the Examples.

A further characteristic feature of this invention is that there can be also obtained polymers having a broad molecular weight distribution suitable for extrusion molding by multistage polymerization having a plurality of polymerization zones where the polymerization conditions such as the temperature and the concentration of hydrogen as the temperature and the concentration of hydrogen are varied.

DETAILED DESCRIPTION OF THE INVENTION

The organomagnesium component (i) which can be used in preparing the catalyst component (A) is a complex of an organomagnesium compound represented by the formula,

    M.sub.α MgR.sub.p.sup.1 R.sub.q.sup.2 X.sub.r.sup.1 X.sub.s.sup.2

wherein

M, R¹, R², X¹, X², α, p, q, r and s are the same as defined above,

with an electron donor represented by D, and the organomagnesium compound includes dihydrocarbyl magnesium R₂ Mg wherein R is a hydrocarbon group and complexes of dihydrocarbyl magnesium with other organometal compounds.

In this formula, R¹ and R² each independently is a hydrocarbon group having 1 to 20 carbon atoms. Exemplary hydrocarbon groups include alkyl groups such as methyl, ethyl, propyl, butyl, amyl, hexyl and decyl groups; cycloalkyl groups such as cyclohexyl group; aryl groups such as phenyl group; and aralkyl groups such as benzyl group. Of these groups, alkyl groups are preferred. M is a metal of the 1st to 3rd groups of the Periodic Table. Exemplary metals represented by M include lithium, sodium, potassium, beryllium, calcium, strontium, barium, zinc, boron and aluminum. Of these metals, lithium, beryllium, boron, aluminum and zinc are preferred due to their ease in making hydrocarbon-soluble organomagnesium complexes. A more preferred metal is aluminum. The atomic ratio of M to Mg, i.e., α may be widely varied including zero but it is preferred to employ hydrocarbon-soluble organomagnesium complexes in which α is 0 to 1.5. It is more preferred to employ hydrocarbon-soluble organomagnesium complexes in which α is 0 to 1. In general, organomagnesium compounds are insoluble in an inert hydrocarbon medium but those with α>0 are soluble in an inert hydrocarbon medium. In order to obtain hydrocarbon soluble organomagnesium compounds in the case of α=0, R¹ and/or R² is a secondary of tertiary alkyl group having at least 3 carbon atoms, or R¹ is an alkyl group having 2 to 6 carbon atoms and R² is an alkyl group having at least 4 carbon atoms and simultaneously the difference in number of carbon atom between R¹ and R² is at least 2. Exemplary organomagnesium compounds with α=0 include (sec-C₄ H₉)₂ Mg, (sec-C₄ H₉)Mg (n-C₄ H₉), (iso-C₃ H₇)Mg(n-C₄ H₉) and (C₂ H.sub. 5)Mg(n-C₄ H₉). Further, a small amount of an oganometal may be added for reducing the viscosity of the dihydrocarbyl magnesium solution.

X¹ and X² each independently is a hydrogen atom or an organic electronegative group containing O, N or S. Exemplary organic electronegative groups include OR¹⁰, OSiR¹¹ R¹² R¹³, NR¹⁴ R¹⁵ and SR¹⁶ groups wherein R¹⁰, R¹⁴, R¹⁵ and R¹⁶ each independently is hydrogen atom or a hydrocarbon group having 1 to 15 carbon atoms and R¹¹, R¹² and R¹³ each independently is a hydrogen atom or a hydrocarbon group having 1 to 15 carbon atoms. Exemplary hydrocarbon groups include alkyl groups such as methyl, ethyl, propyl, butyl, amyl, hexyl and decyl groups; cycloalkyl groups such as cyclohexyl group; aryl groups such as phenyl group; and aralkyl groups such as benzyl group. Of these organic electronegative groups, OR¹⁰ and OSiR¹¹ R¹² R¹³ are preferred. More preferred organic electronegative groups are OR¹⁰ and OSiR¹¹ R¹² R¹³ wherein R¹⁰, R¹¹, R¹² and R¹³ each independently is an alkyl group having 1 to 10 carbon atom or at least one of R¹¹, R¹² and R¹³ is a hydrogen atom and the remaining are alkyl groups having 1 to 10 carbon atoms. α, p, q, r and s each independently is 0 or a number greater than 0 and the relationship of p+q+r+s=mα+2 wherein m is the valence of M is satisfied. This relationship shows stoichiometry between the valence of M plus Mg and the substituents. The range of 0≦(r+s)/(α+1)<2 designates that a total number of X¹ and X² per total number of M and Mg is 0 to 2. It is preferred to employ the organomagnesium compounds containing X¹ or X², i.e. (r+s)>0 in order increase the stability of the component (A) and the catalyst efficiency at high temperatures. A more preferred range is 0.1≦(r+s)/(α+1)≦1.3, and especially 0.3≦(r+s)/(α+1)≦1.

The organomagnesium compounds can be prepared by reacting a compound of R¹ MgQ or R₂ ¹ Mg wherein R¹ is the same as defined above and Q is a halogen atom, with an organometal compound of MR_(m) ², MR_(a) ² X_(b) ¹ X_(c) ² or MQaX_(b) ¹ X_(c) ² wherein, M, R², X¹, X², Q and m are the same as defined above and a+b+c=m, in an inert hydrocarbon medium such as hexane, heptane, octane, cyclohexane, benzene and toluene at a temperature of about 0° C. to about 150° C., and, if necessary or if desired, further reacting the resulting reaction product with an alcohol, siloxane, amine, imine, thiol or a dithio compound. Furthermore, the organomagnesium compound can be prepared by reacting a compound of MgX₂ ¹ or R¹ MgX¹ with a compound of MR_(m) ² or MR_(m-1) ² H or by reacting a compound of R¹ MgX¹ or R₂ ¹ Mg with a compound of R_(n) ² MX_(m-n) ² or X_(a) ¹ MX_(m-a) ² wherein M, R¹, R², X¹, X² and m are the same as defined above and a and n each independently is a number of 0 to m.

The electron donor represented by D is an electron donative organic compound containing O, N, S or P. Exemplary electron donors used in this invention include ethers such as diethyl ether, dibutyl ether, diisoamyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, glycerol trimethyl ether, vinyl methyl ether, tetrahydrofuran, dioxane, crown ether and propylene oxide; siloxanes such as hexamethyldisiloxane, sym-dihydrotetramethyldisiloxane, pentramethyltrihydrotrisiloxane, methylhydrocyclotetrasiloxane, methylhydropolysiloxane, dimethylpolysiloxane and phenylhydropolysiloxane; tertiary amines such as triethylamine, tributylamine, tetramethylethylenediamine, bis(diethylamino)methane, and diazabicylooctane; nitriles such as acetonitrile, propionitrile, acrylonitrile, benzylnitrile and benzonitrile; amides such as dimethylformamide and hexamethylphosphoric triamide; pyridines such as pyridine and methylpyridine; thioethers such as diethyl sulfide, ethylpropyl sulfide, dipropyl sulfide and ethylene sulfide; sulfoxides such as dimethyl sulfoxide, diethyl sulfoxide and dibutyl sulfoxide; phosphines such as triethylphosphine and triphenylphosphine and esters such as ethyl benzoate and ethyl acetate. Of these compounds, ethers, siloxanes and amines are preferred. More preferred are siloxanes.

The suffix t designates the amount of the electron donor coordinated with M or Mg and represents a number greater than zero. In order to obtain a high catalyst efficiency at high temperatures, it is important that the electron donor is coordinated with M or Mg. A preferred t ranges from about 0.05 to about 10, and a more preferred t ranges from about 0.2 to about 2.

The complex of the organomagnesium compound with the electron donor can be easily prepared by contacting the organomagnesium compound with the electron donor at a temperature of about -20° C. to about 100° C. in such an inert hydrocarbon medium as employed in the preparation of the organomagnesium compound.

The aluminum compound (ii) which can be reacted with the organomagnesium component (i) is represented by the formula,

    AlX.sub.x.sup.3 Y.sub.y

wherein X³, Y, x and y are the same as defined above.

A preferred X³ is OR³ or OSiR⁴ R⁵ R⁶. Exemplary hydrocarbon groups having 1 to 20 carbon atoms for R³, R⁴, R⁵, R⁶, R⁷, R⁸ and R⁹ include alkyl groups such as methyl, ethyl, propyl, butyl, amyl, hexyl and decyl; cycloalkyl groups such as cyclohexyl group; aryl groups such as phenyl group; and aralkyl groups such as benzyl group. R⁴, R⁵, R⁶, R⁷ and R⁸ each may be a hydrogen atom.

Y is a chlorine atom, a bromine atom, an iodine atom or a fluorine atom. A preferred Y is a chlorine atom.

The suffixes x and y are 0<x<3, 0<y<3 and x+y=3. In order to efficiently react the component (i) with the aluminum compound (ii) and to prepare a catalyst capable of producing polymers having a narrow molecular weight distribution, x is 1≦x≦2 and at the same time the aluminum compound (ii) is soluble in an inert hydrocarbon medium.

Exemplary aluminum compounds include C₃ H₇ OAlCl₂, C₄ H₉ OAlCl₂, C₅ H₁₁ OAlCl₂, C₆ H₁₃ OAlCl₂, C₇ H₁₄ OAlCl₂, C₈ H₁₇ OAlCl₂, C₉ H₁₉ OAlCl₂ C₁₀ H₂₁ OAlCl₂, C₆ H₅ OAlCl₂, C₆ H₁₁ OAlCl₂, (C₄ H₉ O)₂ AlCl, (C₅ H₁₁ O)₂ AlCl, (C₆ H₁₃ O)₂ AlCl, (C₇ H₁₃ O)₂ AlCl, (C₈ H₁₇ O)₂ AlCl, (C₉ H₁₉ O)₂ AlCl, (C₁₀ H₂₁ O)₂ AlCl, (CH₃)₃ SiOAlCl₂, H.CH₃.C₂ H₅ SiOAlCl₂, H.(CH₃)₂ SiOAlCl₂, (H.CH₃.C₂ H₅ SiO)₂ AlCl, C₄ H₉ SAlCl₂, C₆ H₁₃ SAlCl₂, C₁₀ H₂₁ SAlCl₂, (CH₃)₂ NAlCl₂ and any mixtures thereof.

The compounds (iii) of titanium and the compounds (iii) of vanadium which can be employed include halides, oxyhalides, alkoxyhalides, alkoxides and oxyalkoxides of titanium or vanadium such as titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, ethoxytitanium trichloride, propoxytitanium trichloride, butoxytitanium trichloride, dipropoxytitanium dichloride, dibutoxytitanium dichloride, tripropoxytitanium monochloride, tributoxytitanium monochloride, tetrapropoxytitanium, tetrabutoxytitanium, vanadium tetrachloride, vanadyl trichloride, monobutoxyvanadyl dichloride, dibutoxyvanadyl monochloride, tributoxyvanadyl and, ethoxytrichlorovanadium and any mixture thereof. Of these compounds, compounds of titanium containing at least one chlorine atom, preferably at least three chlorine atoms and compounds of vanadium together with compounds of titanium containing at least three carbon atoms are preferred for obtaining a high catalyst efficiency.

The reaction of the hydrocarbon-soluble organomagnesium component (i), the aluminum compound (ii) and the compound (iii) can be conducted in an inert reaction medium or solvent. Exemplary inert reaction solvents employed in this invention include aliphatic hydrocarbons such as hexane, heptane and octane; aromatic hydrocarbons such as benzene and toluene; alicyclic hydrocarbons such as cyclohexane and cyclomethylhexane; and any mixtures thereof. It is preferred from the viewpoint of the catalyst performances that aliphatic hydrocarbons are employed. With the order of the reaction of these components (i), (ii) and (iii), previous contact of the component (i) with the compound (iii) should be avoided in order for the catalyst to exhibit its high activity. More specifically, the surprising effect of this invention can be accomplished by firstly reacting the component (i) with the aluminum (ii) to form a solid product and secondly contacting the compound (iii) with the surface of the solid product effectively.

The reaction between the component (i) and the aluminum compound (ii) may be carried out by adding these two components into a reaction zone at the same time or by firstly charging one of them into the reaction zone and secondly adding the other into the reaction zone. The reaction temperature was not particularly limited and typically ranges from about -50° C. to about 150° C. A preferred reaction temperature ranges from about 0° C. to about 100° C. from the viewpoint of the progress of reaction. The mol ratio of the aluminum compound (ii) to the component (i) which can be employed in this invention is not particularly limited and typically ranges from about 0.01 to about 100. A preferred mol ratio of the aluminum compound (ii) to the component (i) ranges from about 0.1 to about 20. The solid product obtained by the reaction between the component (i) and the aluminum compound (ii) may be usually separated by filtration or washed by decantation and then supplied to the contact with the compound (iii). In order to simplify the reaction procedure, it is preferred that the compound (iii) is added to the reaction solution obtained after completion of the reaction between the component (i) and the aluminum compound (ii), and further the contact with the compound (iii) is continued.

In order to impart a high catalyst activity at high temperatures to the catalyst, it is essential to control the amount of the compound (iii) employed and the concentration of the compound (iii) in the reaction solution. The atomic ratio of Mg/(Ti+V) which is used in this invention ranges from about 3 to about 500, and a preferred atomic ratio of Mg/(Ti+V) ranges from about 5 to about 200. A more preferred atomic ratio of Mg/(Ti+V) ranges from about 10 to about 100. The concentration of Ti plus V in the reaction solution used in this invention is at most 2 mols per liter of the inert reaction solvent. A preferred concentration of Ti plus V in the reaction solution ranges from about 0.01 to about 100 mmols per liter of the inert reaction solvent. The temperature for contacting the solid product formed by the reaction between the component (i) and the aluminum compound (ii) with the compound (iii) is not particularly limited and typically ranges from about -50° C. to about 150° C., preferably from about 0° C. to about 95° C.

The component (A) of this invention becomes an excellent catalyst for polymerizing an olefin in combination of an organometal component (B).

Exemplary organometal components (B) which can be used in this invention are organoaluminum compound including trialkylaluminums such as Al(C₂ H₅)₃, Al(C₃ H₇)₃, Al(C₄ H₉)₃, Al(C₅ H₁₁)₃, Al(C₆ H₁₃)₃, Al(C₈ H₁₇)₃ and Al(C₁₀ H₂₁)₃, alkylaluminum hydrides such as Al(C₂ H₅)₂ H and Al(i-C₄ H₉)₂ H, alkylaluminum halides such as Al(C₂ H₅)₂ Cl, Al(C₂ H₅)Cl₂, Al(i-C₄ H₉)₂ Cl and Al(C₂ H₅)₂ Br, alkyaluminum alkoxides such as Al(C₂ H₅)₂ (OC₂ H₅) and Al(i-C₄ H₉)₂ (OC₄ H₉), alkylaluminum siloxides such as Al(C₂ H₅)₂ (OSiH.CH₃.C₂ H₅) and Al(i-C₄ H₉)[OSi(CH₃)₂ (i-C₄ H₉)]₂, reaction products of a trialkylaluminum and a conjugated diene such as aluminum isoprenyl and aluminum myrcenyl; organoboron compounds such as trialkylborons such as B(C₂ H₅)₃, B(C₃ H₇)₃, B(C₄ H₉)₃, B(C₆ H₁₃)₃ and B(C₈ H₁₇)₃, triarylborons such as B(C₆ H₅)₃, alkylboron alkoxides such as B(C₂ H₅)₂ (OC₂ H₅) and B(C₅ H₁₁)₂ (OC₄ H₉) and alkylboron halides such as B(C₇ H₁₅)₂ Cl; organozinc compounds such as dialkylzincs including Zn(C₂ H₅)₂, Zn(C₄ H₉)₂, Zn(C₆ H₁₃)₂, Zn(C₈ H₁₇)₂ and Zn(C₂ H₅)(n-C₃ H₇), diarylzincs such as Zn(C₆ H₅)₂ and alkylzinc alkoxides such as Zn(C₃ H₇)(OC₄ H₉); the same organomagnesium compounds as described above, and any mixtures thereof. Of these organometal compounds, organoaluminum compounds are preferred, and trialkylaluminums are more preferred. The component (A) and the organometal component (B) may be added under the polymerization conditions to the polymerization system of may be combined prior to the polymerization.

The mol ratio of the organometal component (B) to (Ti+V) in the component (A) typically ranges from about 3 to about 1,000 and preferably ranges from about 5 to about 500.

The catalyst of this invention is suitable for the polymerization of ethylene and may also be employed for the copolymerization of ethylene with another α-olefin having 3 to 20 carbon atoms such as propylene, butene-1, isobutene, hexene-1, 4-methylpentene-1, octene-1 and or with a polyene such as butadiene and isoprene. In the copolymerization it is preferred to employ the mol ratio of the α-olefin to be copolymerized to ethylene of at most 5. According to this invention it is possible to produce polyethylene having a density of about 0.975 to about 0.910 by the homo- or co-polymerization of ethylene.

In this invention, polymerization is conducted at a temperature ranging from about 120° C. to about 320° C., preferably from about 150° C. to about 300° C. by the solution polymerization method. As the polymerization medium or solvent there can be employed aliphatic hydrocarbons such as hexane, heptane or octane; aromatic hydrocarbon such as benzene, toluene or xylene; and alicyclic hydrocarbons such as cyclohexane or methylcyclohexane. The catalyst is introduced into a reactor together with the polymerization solvent and ethylene is added at a pressure of ethylene of from about 0.1 to about 40 MPa, preferably from about 1 to about 25 MPa in an inert atmosphere and polymerized. Also it is possible to employ such a means as a stirrer for providing better contact between ethylene and the catalyst in the polymerization.

In this invention there may be employed single stage polymerization having one polymerization zone or multistage polymerization having a plurality of polymerization zones. The catalyst of this invention can provide polyethylene having a narrow molecular weight distribution in the single stage polymerication and polyethylene having a broad molecular weight distribution in the multistage polymerization.

In order to control the molecular weight of the polymer, the temperature of the reactor may be varied or it is also possible to add hydrogen or an organic compound which can easily cause chain transfer. Furthermore, the process of this invention may be combined with a method of using a titanate as a third component for controlling the density of the polymer formed.

The present invention will now be illustrated in greater detail with reference to several Examples, but they are given for illustrative purposes only and are not to be construed as limiting the invention.

In these examples MI designates a melt index of a polymer which is measured at 190° C. under a load of 2.16 Kg in accordance with ASTM D-1238. FR designates a flow ratio represented by MI₂₁.6 /MI₂.16 wherein MI₂₁.6 is a melt index of the polymer measured at 190° C. under a load of 21.6 Kg and MI₂.16 is the melt index measured at 190° C. under a load of 2.16 Kg and is one of the criteria for the molecular weight distribution. A lower FR shows a narrower molecular weight distribution. The term "catalyst efficiency" shows the amount of polymer formed in kilogram per gram of Ti plus V per hour.

EXAMPLE 1 (I) Synthesis of Hydrocarbon-soluble Organomagnesium Component (i)

In a 200 ml flask purged with nitrogen were charged 5 g of magnesium powder, and then 20 ml out of a mixed solution of 20.8 ml of n-butyl chloride and 60 ml of n-octane were added thereto. The flask was heated and the resulting mixture was refluxed with stirring. After the reaction was started, the remaining mixed solution of n-butyl chloride and n-octane was added dropwise to the flask over two hours under refluxing. After completion of the reaction, the reaction mixture was stirred further for one hour, and 20 ml of a n-octane solution containing 35 mmols of AlCl₂ (On-C₃ H₇) was added thereto and the reaction was continued at 70° C. for two hours to give an organomagnesium component solution. As a result of analysis, the composition of this complex was AlMg₀.5 (n-C₄ H₉)₂.9 (On-C₃ H₇)₀.5 and the concentration of the organometal was 1.0 mol per liter of the reaction solvent.

The AlCl₂ (On-C₃ H₇) employed was prepared by reacting aluminum powder, AlCl₃ and n-C₃ H₇ OH at a mol ratio of 1:2:3 in heptane.

(II) Synthesis of Component (A)

The oxygen and moisture present inside a 250 ml flask equipped with a dropping funnel and a water-cooled reflux condenser were purged with nitrogen, and to the flask were charged 24 ml of a n-octane solution containing dichlorobutoxy aluminum in an amount of 0.2 ml per liter of n-octane and 30 ml of n-octane in a nitrogen atomosphere and the temperature was raised to 70° C. Then 20 ml of a n-octane solution containing 4.0 ml of the organomagnesium component (i) were accurately measured, charged in the dropping funnel and added dropwise to the flask at 70° C. with stirring over two hours, resulting in a white suspension reaction solution. To this suspension reaction solution were added 22 ml of a n-octane solution containing 0.16 mmol of titanium tetrachloride at a concentration of titanium of 1.6 mmols per liter of n-octane and the reaction was continued at 70° C. for one hour.

(III) Polymerization of Ethylene

In a 1 l autoclave evacuated were charged 3.0 ml of the component (A) as obtained above and 0.144 mmol of trioctyl aluminum with 0.6 l of dehydrated and deaerated n-octane, and then 50 mmols of hydrogen were introduced into the autoclave. While keeping the temperature of the autoclave at 160° C., ethylene was introduced into the autoclave at a pressure of 4.0 MPa and the polymerization was carried out for 40 minutes while maintaining the total pressure constant by supplying additional ethylene, resulting in 81 g of a polymer. The catalyst efficiency was 527 Kg/g Ti.Hr., MI was 2.6, FR was 18, the density was 0.969 g/cc.

EXAMPLE 2 (I) Synthesis of Component (A)

The oxygen and moisture present inside a 250 ml flask equipped with a dropping funnel and a water-cooled reflux condenser were purged with nitrogen, and to the flask were charged 55 ml of a n-octane solution containing 6 mmols of AlCl₂ [OSiH(CH₃)₂ ] in a nitrogen atmosphere and the temperature was raised to 65° C. Then 25 ml of a n-octane solution containing, as the organomagnesium component (i), Al₀.18 Mg(n-C₄ H₉)₂.18 (On-C₈ H₁₇)₀.36 were accurately measured, charged in the dropping funnel and added dropwise to the flask at 65° C. with stirring over one hour, resulting in a white suspension reaction solution. To the obtained suspension reaction solution were added 20 ml of a n-octane solution containing 0.1 mmol of titanium tetrachloride and 0.05 mmol of vanadyl trichloride at a concentration of titanium and vanadium of 1.5 mmols per liter of n-octane and the reaction was continued at 70° C. for two hours.

(II) Polymerization of Ethylene

In a 1 l autoclave evacuated were charged 2.0 ml of the component (A) as obtained above and 0.144 mmol of trioctyl aluminum with 0.6 l of dehydrated and deaerated hexane, and then 20 mmols of hydrogen were introduced into the autoclave. While keeping the temperature of the autoclave at 160° C., ethylene was introduced into the autoclave at a pressure of 4.0 MPa and the polymerization was carried out for 40 minutes while maintaining the total pressure constant by supplying additional ethylene, resulting in 79 g of a polymer. The catalyst efficiency was 538 Kg/g (Ti+V).Hr,MI was 1.7, FR was 23, the density was 0.969 g/cc.

EXAMPLES 3 to 16

Components (A) were prepared by reacting the organomagnesium component (i) with the aluminum compound (ii) under the reaction conditions as set forth in Table 1 and subsequently contacting the obtained product with the compound (iii) under the reaction conditions as set forth in Table 1 in the same manner as described in Example 2. Using 3 ml of these components (A) and organometal components (B) as set forth in Table 2 under the reaction conditions as set forth in Table 2, polymerization of ethylene was carried out under the polymerization conditions as set forth in Table 2 in the same manner as in Example 2. The results are shown in Table 2.

                                      TABLE 1                                      __________________________________________________________________________                                               (i) + (ii)                                                                     Reaction                                                                       Conditions                                                                     Temper-                              Example                                                                             Organomagnesium Component (i)                                                                         Aluminum Compound (ii)                                                                       ature                                                                               Time                            No.  (mmol)                 (mmol)        (°C.)                                                                        (hour)                          __________________________________________________________________________     3    Al.sub.0.25 Mg(n-C.sub.4 H.sub.9).sub.1.75 (On-C.sub.6 H.sub.13)                                      n-C.sub.5 H.sub.11 OAlCl.sub.2                                                               80   3                                    4.0                    20.0                                               4    (sec-C.sub.6 H.sub.13).sub.1.7 Mg[OSiH(CH.sub.3).sub.2 ].sub.0.3                                      n-C.sub.3 H.sub.7 OAlCl.sub.2                                                                80   2                                    4.0                    10.0                                               5    (C.sub.2 H.sub.5).sub.0.8 Mg(n-C.sub.4 H.sub.9).sub.0.8 (On-C.sub.8            H.sub.17).sub.0.4      [(C.sub.2 H.sub.5)(CH.sub.3)HSi]AlCl.sub.2                                                   100  1                                    4.0                    3.6                                                6    Li.sub.0.1 Mg(sec-C.sub.4 H.sub.9).sub.0.91 (n-C.sub.4 H.sub.9).sub.0          .91 (On-C.sub.5 H.sub.11).sub.0.28                                                                    n-C.sub.8 H.sub.17 OAlCl.sub.2                                                                0   5                                    4.0                    120                                                7    ZnMg(C.sub.2 H.sub.5).sub.1.8 [OSiH(CH.sub.3).sub.2 ].sub.2.2                                         (n-C.sub.6 H.sub.13 O).sub.1.5 AlCl.sub.1.5                                                  30   10                                   4.0                    0.2                                                8    B.sub.0.1 Mg(n-C.sub.10 H.sub.21).sub.0.98 (On-C.sub.4 H.sub.9).sub.           1.32                   (n-C.sub.3 H.sub.7 O)(n-C.sub.10 H.sub.21                                      O)AlCl        60   4                                    4.0                    60.0                                               9    Be.sub.0.1 Mg(n-C.sub.3 H.sub.7).sub.2.2 (On-C.sub.5 H.sub.11).sub.0.          3                      (CH.sub.3).sub.2 NAlCl.sub.2                                                                 60   4                                    4.0                    1.2                                                10   AlMg(C.sub.2 H.sub.5).sub.1.6 (n-C.sub.6 H.sub.13).sub.0.6 (On-C.sub.          4 H.sub.9).sub.2.8     (n-C.sub.7 H.sub.15).sub.0.5 AlCl.sub.2.5                                                    140  2                                    4.0                    1.1                                                11   Mg(sec-C.sub.5 H.sub.11).sub.1.9 (SC.sub.6 H.sub.5).sub.0.1                                           (n-C.sub.10 H.sub.21 S).sub.2 AlCl                                                           50   5                                    4.0                    180.0                                              12   Mg(C.sub.2 H.sub.5)(n-C.sub.4 H.sub.9)[O(n-C.sub.4 H.sub.9).sub.2              ].sub.0.4              [(CH.sub.3).sub.2 HSiO]AlCl.sub.2                                                            40   2                                    4.0                    15.0                                               13   Al.sub.0.1 Mg(n-C.sub.6 H.sub.13).sub.2.0 (On-C.sub.4 H.sub.9).sub.0.          3 .                    [(CH.sub.3).sub.2 HSiO]AlCl.sub.2                                                            100  2                                    [O(i-C.sub.5 H.sub.11).sub.2 ].sub.0.8                                                                12.0                                                    4.0                                                                       14   Al.sub.0.2 Mg(C.sub.2 H.sub.5).sub.1.6 (n-C.sub.4 H.sub.9)                                            [(CH.sub.3).sub.2 HSiO]AlCl.sub.2                                                            85   4                                    [ (CH.sub.3).sub.2 HSiOSiH(CH.sub.3).sub.2 ].sub.1.2                                                  30.0                                                    4.0                                                                       15   Al.sub.0.2 Mg(C.sub.2 H.sub.5).sub.1.6 (n-C.sub.4 H.sub.9)                                            [(CH.sub.3).sub.2 HSiO]AlCl.sub.2                                                            "    "                                    [(CH.sub.3).sub.2 HSiOSiH(CH.sub.3).sub.2 ].sub.1.2                                                   30.0                                                    4.0                                                                       16   Al.sub.0.2 Mg(C.sub.2 H.sub.5).sub.1.6 (n-C.sub.4 H.sub.9)                                            [(CH.sub.3).sub.2 HSiO]AlCl.sub.2                                                            "    "                                    [(CH.sub.3).sub.2 HSiOSiH(CH.sub.3).sub.2 ].sub.1.2                                                   30.0                                                    4.0                                                                       __________________________________________________________________________                                               [(i) + (ii)] +                                                                 (iii)                                                                  Concentration                                                                          Reaction                                                               of Titanium                                                                            Conditions                                                             plus Vanadium                                                                          Temper-                                              Example                                                                             Compound (iii)                                                                              (mmol per liter                                                                        ature                                                                               Time                                            No.  (mmol)       of solvent                                                                             (°C.)                                                                        (hour)                          __________________________________________________________________________                     3    TiCl.sub.3 (Oi-C.sub.3 H.sub.7)                                                             1.6     90   3                                                    0.16                                                                      4    TiCl.sub.4 + VOCl.sub.3                                                                     2.0     60   1                                                    0.10   0.10                                                               5    TiCl.sub.4 + VO(On-C.sub.4 H.sub.9).sub.3                                                    0.44   60   1                                                    0.011  0.033                                                              6    TiCl.sub.4    0.13   40   5                                                    0.013                                                                     7    TiCl.sub.4   3.3     20   5                                                    0.330                                                                     8    TiCl(On-C.sub.4 H.sub.9).sub.3                                                               0.18    0   8                                                    0.018                                                                     9    VOCl.sub.3 + TiBr.sub.4                                                                     6.4     90   2                                                    0.320   0.320                                                             10   VCl.sub.4    5.0     100  4                                                    0.50                                                                      11   Ti(On-C.sub.4 H.sub.9).sub.4                                                                4.5     -20  9                                                    0.45                                                                      12   TiCl.sub.2 (Oi-C.sub.3 H.sub.7).sub.2                                                       0.5OCl.sub.3                                                                           70   1                                                    0.025        0.025                                                        13   TiCl.sub.4   3.0     60   1                                                    0.30                                                                      14   TiCl.sub.4 + VO(Oi-C.sub.3 H.sub.7).sub.3                                                   3.5     80   3                                                    0.2   0.15                                                                15   TiCl.sub.4 + VO(Oi-C.sub.3 H.sub.7).sub.3                                                   "       "    "                                                    0.2   0.15                                                                16   TiCl.sub.4 + VO(Oi-C.sub.3 H.sub.7).sub.3                                                   "       "    "                                                    0.2   0.15                                                __________________________________________________________________________

                                      TABLE 2                                      __________________________________________________________________________                        Polymerization Conditions                                                                       Result of Polymerization                                      Polymerization                                                                         Ethylene Catalyst                                   Example                                                                             Organometal Compound (B)                                                                     Temperature                                                                            Pressure                                                                            H.sub.2                                                                            Efficiency                                 No.  (mmol)        (°C.)                                                                           (MPa)                                                                               (mmol)                                                                             Kg/g(Ti + V) . Hr                                                                        MI FR                            __________________________________________________________________________     3    Al(C.sub.2 H.sub.5).sub.3                                                                 0.48                                                                              160     4.0  50  389       3.6                                                                               19                            4    Al(C.sub.2 H.sub.5).sub.3                                                                 0.90                                                                              160     4.0  50  369       4.2                                                                               20                            5    Al(C.sub.2 H.sub.5).sub.3                                                                 0.33                                                                              160     4.0  40  424       1.3                                                                               18                            6    Al(i-C.sub.4 H.sub.9).sub.3                                                               0.06                                                                              160     4.0  40  306       15.2                                                                              20                            7    Al(i-C.sub.4 H.sub.9).sub.3                                                               0.10                                                                              160     4.0  60  312       1.6                                                                               18                            8    Al(n-C.sub.8 H.sub.17).sub.3                                                              0.16                                                                              140     3.0  80  211       2.1                                                                               23                            9    Al(C.sub.2 H.sub.5).sub.2.5 Cl.sub.0.5                                                    0.08                                                                              140     3.0  80  137       5.5                                                                               26                            10   Al(C.sub.2 H.sub.5).sub.2.6 (OC.sub.2 H.sub.5).sub.0.4                                    1.50                                                                              140     4.0  70  109       9.4                                                                               28                            11   Aluminum isoprenyl                                                                        0.20                                                                              140     4.0  90  218       35.2                                                                              25                            12   AlMg(C.sub.2 H.sub.5).sub.4 (n-C.sub.4 H.sub.9)                                           0.54                                                                              180     4.0  15  326       17.5                                                                              20                            13   Al(n-C.sub.10 H.sub.21).sub.3                                                             0.08                                                                              160     4.0  30  406       0.9                                                                               18                            14   Al(i-C.sub.4 H.sub.9).sub.3                                                               0.30                                                                              160     4.0  50  449       6.5                                                                               19                            15   Zn(C.sub.2 H.sub.5).sub.3                                                                 2.5                                                                               140     2.0  80  154       9.8                                                                               35                            16   B(n-C.sub.4 H.sub.9).sub.3                                                                3.6                                                                               140     3.0  60  117       2.6                                                                               29                            __________________________________________________________________________

EXAMPLE 17

Using 4 ml of the same component (A) as in Example 1 and 0.04 mmol of triethyl aluminum, 1.2 mols of ethylene were polymerized at 140° C. at a pressure of ethylene of 2.0 MPa in the presence of 2 mmols of hydrogen. After 200 mmols of hydrogen were introduced into the autoclave and the temperature was raised to 200° C., 1.0 mol of ethylene was further polymerized at a pressure of ethylene of 2.0 MPa, resulting in a polymer having a MI of 0.8 and a FR of 96.

EXAMPLE 18

In the same manner as in Example 1, 1.0 mol of ethylene was polymerized at 150° C. at a pressure of ethylene of 2.0 MPa in the presence of 2 mmols of hydrogen by using 3 ml of the same component (A) as in Example 2 and 0.02 mmol of triethyl aluminum. After 150 mmols of hydrogen were introduced into the autoclave and the temperature was raised to 190° C., 1.0 mol of ethylene was further polymerized at a pressure of ethylene of 3.0 MPa, resulting in a polymer having a MI of 1.1 and a FR of 89.

EXAMPLES 19 TO 24

A component (A) was prepared in the same manner as in Example 1 except that 2 mmols of Al₀.33 Mg(n-C₄ H₉)₂ (On-C₆ H₁₃), 1.5 mmols of n-C₄ H₉ OAlCl₂ and 0.10 mmol of TiCl₄ at a concentration of titanium of 1.0 mmol per liter of the reaction solvent were used. In a 1 l autoclave evacuated were charged 5 ml of the obtained component (A) and 0.08 mmol of Al(C₂ H₅)₃ with 0.6 l of dehydrated and deaerated hexane. After 16 mmols of hydrogen and an olefin or a polyene as set forth in Table 3 were introduced into the autoclave, the temperature was raised to 155° C. and ethylene was added up to a pressure of 3.0 MPa. Copolymerization of ethylene was conducted for 30 minutes while maintaining the total pressure constant by supplying additional ethylene. The results are shown in Table 3.

                                      TABLE 3                                      __________________________________________________________________________                       Catalyst   Products                                          Example                                                                             α-Olefin or Polyene                                                                   Efficiency       Density                                     No.  (mmol)       [Kg/g (Ti + V) . Hr]                                                                      MI FR (g/cc)                                      __________________________________________________________________________     19   Propylene 100                                                                               294        3.4                                                                               20 0.941                                       20   4-Methylpentene-1                                                                        50 386        9.6                                                                               19 0.954                                       21   Hexene-1  200                                                                               305        18.3                                                                              19 0.930                                       22   Octene-1  400                                                                               266        2.5                                                                               22 0.923                                       23   Butene-1  100                                                                               297        1.9                                                                               18 0.946                                       24   Butadiene 50 208        0.9                                                                               19 0.951                                       __________________________________________________________________________

EXAMPLES 25 TO 30

A component (A) was prepared in the same manner as in Example 1 using 2.0 mmols of Al₀.33 Mg (n-C₄ H₉)₂ (On-C₆ H₁₃), 1.5 mmols of [(C₂ H₅)(CH₃)HSiO]AlCl₂, 0.10 mmol of TiCl₄ and 0.10 mmol of VOCl₂ (On-C₄ H₉) at a concentration of titanium and vanadium of 2.0 mmols per liter of the reaction solvent. In a 1 l autoclave eacuated were charged 5 ml of the obtained component (A) and 0.12 mmol of Al(C₂ H₅)₃ with 0.6 l of dehydrated and deaerated hexane. After 20 mmols of hydrogen and an α-olefin or a polyene as set forth in Table 4 were introduced into the autoclave, the temperature was raised to 150° C. and ethylene was added up to a pressure of 3.0 MPa. Copolymerization of the α-olefin or polyene with ethylene was conducted for 30 minutes while maintaining the total pressure constant by supplying additional ethylene. The results are shown in Table 4.

                  TABLE 4                                                          ______________________________________                                                      Results of Polymerization                                         α-Olefin         Products                                                     or            Catalyst              Den-                                       Polyene       Efficiency            sity                                  No.  (mmol)        [Kg/g(Ti + V)]                                                                             MI   FR   (g/cc)                                ______________________________________                                         25   4,4-Dimethyl- 315         2.7  25   0.938                                      pentene-1                                                                      100                                                                       26   Butene-1      287         8.5  20   0.946                                      150                                                                       27   Octene-1      269         17.5 19   0.930                                      300                                                                       28   Decene-1      308         21.5 21   0.920                                      400                                                                       29   4-Methylpentene-1                                                                            299         7.9  20   0.936                                      150                                                                       30   Isoprene      205         0.8  24   0.955                                      70                                                                        ______________________________________                                    

It will be appreciated that the instant specification and examples are set forth by way of illustration and not limitation, and that various modifications and changes may be made without departing from the spirit and scope of the present invention. 

What is claimed is:
 1. A process for polymerizing an α-olefin comprising contacting the olefin in liquid phase at a temperature of about 120° to 320° C. with a catalyst comprising a component (A) and an organometal component (B), the component (A) being produced by reacting a hydrocarbon-soluble organomagnesium component (i) of the formula,

    M.sub.α MgR.sub.p.sup.1 R.sub.q.sup.2 X.sub.r.sup.1 X.sub.s.sup.2 D.sub.t

wherein α, p, q, r, s and t each independently is 0 or a number greater than 0, p+q+r+s=mα+2, 0≦(r+s)/(α+1)<2, m is the valence of M, M is a metal of the 1st to 3rd groups of the Periodic Table, R¹ and R² each independently is a hydrocarbon group having 1 to 20 carbon atoms, X¹ and X² each independently is a hydrogen atom or an organic electronegative group containing O, N or S, D is an electron donor, with an aluminum compound (ii) of the formula,

    AlX.sub.x.sup.3 Y.sub.y

wherein X³ is OR³, OSiR⁴ R⁵ R⁶, NR⁷ R⁸ or SR⁹ wherein R³ and R⁹ each independently is a hydrocarbon group having 1 to 20 carbon atoms and R⁴, R⁵, R⁶, R⁷ and R⁸ each independently is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, Y is a halogen atom, x and y each independently is a number greater than 0 and less than 3, x+y=3,and contacting the product of (i)+(ii) with (iii) a compound of tetravalent titanium and/or a compound of vanadium at a concentration of titanium plus pentavalent or tetravalent vanadium of at most about 2 mols per liter of an inert reaction solvent, the atomic ratio of Mg/(Ti+V) in (A) being about 3 to about
 500. 2. A process of claim 1, wherein M in the organomagnesium component (i) of the component (A) is lithium, berylium, boron, aluminum or zinc metal.
 3. A process of claim 2, wherein M in the organomagnesium component (i) of the component (A) is aluminium metal.
 4. A process of claim 1, wherein α in the organomagnesium component (i) is 0≦α≦1.5.
 5. A process of claim 4, wherein α in the organomagnesium component (i) is 0<α≦1.
 6. A process of claim 1, wherein X¹ and X² in the organomagnesium component (i) each independently is OR¹⁰, OSiR¹¹ R¹² R¹³, NR¹⁴ R¹⁵ or SR¹⁶ wherein R¹⁰, R¹⁴, R¹⁵ and R¹⁶ each independently is a hydrocarbon group having 1 to 15 carbon atoms and R¹¹, R¹² and R¹³ each independently is a hydrogen atom or a hydrocarbon group having 1 to 15 carbon atoms.
 7. A process of claim 6, wherein X¹ and X² in the organomagnesium component (i) each independently is OR¹⁰.
 8. A process of claim 6, wherein X¹ and X² in the organomagnesium component (i) each independently is OSiR¹¹ R¹² R¹³.
 9. A process of claim 1, wherein the amount of X¹ and X² in the organomagnesium component (i) is 0.1<(r+s)/(α+1)≦1.3.
 10. A process of claim 9, wherein the amount of X¹ and X² in the organomagnesium component (i) is 0.3≦(r+s)/(α+1)≦1.0.
 11. A process of claim 1, wherein the electron donor represented by D is an electron donative organic compound containing O, N, S or P.
 12. A process of claim 11, wherein the electron donative organic compound is an ether, a siloxane, a tertiary amine, a nitrile, an amide, a pyridine, a thioether, a sulfoxide or a phosphine.
 13. A process of claim 12, wherein the electron donative organic compound is an ether.
 14. A process of claim 12, wherein the electron donative organic compound is a siloxane.
 15. A process of claim 12, wherein the electron donative organic compound is an amine.
 16. A process of claim 1, wherein t in the organomagnesium component (i) is about 0.05 to about
 10. 17. A process of claim 1, wherein t in the organomagnesium component (i) is about 0.2 to about
 2. 18. A process of claim 1, wherein X³ in the aluminum compound (ii) is OR³.
 19. A process of claim 1, wherein X³ in the aluminum compound (ii) is OSiR⁴ R⁵ R⁶.
 20. A process of claim 1, wherein Y in the aluminum compound (ii) is a chlorine atom.
 21. A process of claim 1, wherein, x in the aluminum compound (ii) is 1≦x≦2 and the aluminum compound (ii) is soluble in a hydrocarbon solvent.
 22. A process of claim 1, wherein (iii) the compound of titanium contains at least one chlorine atom.
 23. A process of claim 22, wherein (iii) the compound of titanium contains at least three chlorine atoms.
 24. A process of claim 1, wherein, as (iii) the compound of titanium and/or the compound of vanadium, a compound of titanium containing at least three chlorine atoms and a compound of vanadium are employed.
 25. A process of claim 1, wherein the reaction between the component (i) and the aluminum compound (ii) is conducted at a temperature of about -50° to about 150° C.
 26. A process of claim 1, wherein the mol ratio of the compound (ii) to the component (i) is about 0.01 to about
 100. 27. A process of claim 1, wherein the mol ratio of the compound (ii) to the component (i) is about 0.1 to about
 20. 28. A process of claim 1, wherein the contact of the reaction product of (i)+(ii) with (iii) the compound of titanium and/or the compound of vanadium is conducted at a temperature of about -50° to about 150° C.
 29. A process of claim 28, wherein the contact of the reaction product of (i)+(ii) with (iii) the compound of titanium and/or the compound of vanadium is conducted at a temperature of about 0° to about 95° C.
 30. A process of claim 1, wherein the atomic ratio of Mg/(Ti+V) in the component (A) is about 5 to about
 200. 31. A process of claim 30, wherein the atomic ratio of Mg/(Ti+V) in the component (A) is about 10 to about
 100. 32. A process of claim 1, wherein the reaction product of the component (i) and the aluminum compound (ii) is contacted with (iii) the compound of titanium and/or the compound of vanadium at a concentration of titanium plus vanadium of about 0.01 mmol to about 100 mmols per liter of the inert reaction solvent.
 33. A process of claim 1, wherein the organometal component (B) is an organoaluminum compound, an organoboron compound, an organozinc compound or an organomagnesium compound.
 34. A process of claim 33, wherein the organometal component (B) is an organoaluminum compound.
 35. A process of claim 33, wherein the organoaluminum compound is a trialkylaluminum, an alkylaluminum hydride, an alkylaluminum halide, an alkylaluminum alkoxide, an alkylaluminum siloxide and a reaction product of a trialkylaluminum and a conjugated diene.
 36. A process of claim 1, wherein the mol ratio of the organometal compound (B) to (Ti+V) in the component (A) is about 3 to about
 1000. 37. A process of claim 1, wherein the α-olefin is ethylene.
 38. A process of claim 37, wherein the polymerization of ethylene is carried out at a partial pressure of ethylene of about 1 to about 25 MPa at a polymerization temperature of about 150° to about 300° C.
 39. A process of claim 1, wherein copolymerization of ethylene with an α-olefin other than ethylene or a polyene.
 40. A process of claim 39, wherein the α-olefin other than ethylene is a C₃₋₂₀ α-olefin.
 41. A process of claim 39, wherein the polyene is butadiene or isoprene.
 42. A process of claim 39, wherein the mol ratio of the α-olefin or polyene to ethylene is at most
 5. 43. A process of claim 1, wherein the polymerization of an α-olefin is conducted in a plurality of polymerization zones.
 44. A process of claim 1, wherein the polymerization temperature is about 160° C.
 45. A catalyst useful for polymerizing an α-olefin comprising a component (A) and an organometal component (B), the component (A) being produced by reacting a hydrocarbon-soluble organomagnesium component (i) of the formula

    M.sub.α MgR.sub.p.sup.1 R.sub.q.sup.2 X.sub.r.sup.1 X.sub.s.sup.2 D.sub.t

wherein α, p, q, r, s and t each independently is 0 or a number greater than 0, p+q+r+s=mα+2, 0≦(r+s)/(α+1)<2, m is the valence of M, M is a metal of the 1st to 3rd groups of the Periodic Table, R¹ and R² each independently is a hydrocarbon group having 1 to 20 carbon atoms, X¹ and X² each independently is hydrogen or an organic electronegative group containing O, N or S, D is an electron donor, with an aluminum compound (ii) of the formula,

    AlX.sub.x.sup.3 Y.sub.y

wherein X³ is OR³, OSiR⁴ R⁵ R⁶, NR⁷ R⁸ or SR⁹ wherein R³ and R⁹ each independently is a hydrocarbon group having 1 to 20 carbon atoms and R⁴, R⁵, R⁶, R⁷ and R⁸ each independently is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, Y is a halogen atom, x and y each independently is a number greater than 0 and less than 3, x+y=3,and contacting the product of (i)+(ii) with (iii) a compound of titanium tetravalent and/or a compound of vanadium at a concentration of titanium plus pentavalent or tetravalent vanadium of at most about 2 mols per liter of an inert reaction solvent, the atomic ratio of Mg/(Ti+V) in (A) being about 3 to about
 500. 